Postpartum depression and risk factors among working women one year after delivery in Beijing, China: a cross-sectional study

Background Postpartum depression (PPD) is the most common mental illness affecting women after childbirth, and working mothers may be faced with unique challenges. This study aimed to examine the depression status among working postpartum women in 1 year of childbirth and explore the relationship between occupational factors and PPD in urban Beijing, China. Methods A cross-sectional survey of 554 postpartum women was conducted among ten community health service centers in six urban districts of Beijing, China. Sociodemographic, occupational, childbirth and postpartum information were collected. Depression status was obtained using the Edinburgh Postnatal Depression Scale. Prevalence of postpartum depression (PPD) was assessed in relation to occupational characteristics, and influencing factors were analyzed through logistic regression. Results Of the postpartum women, 29.42% met the criteria for depression. PPD prevalence was significantly higher among women employed in commercial enterprises (39.81%). The analysis of influencing factors showed that age, family or personal monthly income, maternity leave, feeding methods, and postpartum care affected the psychological health of occupational women after childbirth. Conclusion PPD prevalence is notably elevated among women employed in commercial enterprises, and specific risk factors contribute to its occurrence. These findings highlight the need for targeted interventions to address these risk factors and prevent PPD in this population.


Introduction
China has the largest number of female workers in the world, representing approximately 26% of the global female employment total (1).The female employment rate in China also ranks among the highest worldwide.According to data from the National Bureau of Statistics of China, in 2021, there were 320 million employed women in the country, constituting 43.1% of the total workforce (2).This proportion consistently surpasses that of Asia-Pacific nations such as South Korea (42.7%) and Singapore (41.2%), as well as the global average (39.3%).It is comparably aligned with that of Western developed countries such as the United States (46.2%) and Sweden (47.4%) (1).The health of these female workers, particularly in terms of mental well-being, is a critical concern.
Postpartum depression (PPD) is the most common mental health issue affecting women after childbirth, with symptoms persisting for up to 1 or 2 years (3).PPD symptoms, such as sadness, irritability, anxiety, and poor appetite, can escalate to severe agitation and in extreme cases, self-harm or infanticide (3,4).This condition not only affects the well-being of the mother but also poses significant risks to the newborn and affecting the socio-emotional dynamics of the family.This underscores the necessity for proactive attention and effective interventions.
Well-established risk factors associated with developing PPD include age, low education level, low socioeconomic status, limited social support, relationship difficulties, a history of depression and depression during the pregnancy (5,6).Hormonal fluctuations, nutritional deficiencies, sleep disturbances are also contributing factors to PPD (7).While these risks are universal among all new mothers, working mothers are faced with unique challenges.Typically, most professional women return to work within the first year postdelivery, which largely depended on the duration and terms of maternity leave.The features of maternity leave, such as length, wage replacement and employment protection, significantly impact maternal mental health (8, 9).Moreover, workplace conditions, including work schedules, shift work, reward structures, and workfamily conflict, can act as stressors, heightening the risk of depression (10).Due to the dual demands of infant care and employment, working mothers are particularly susceptible to workplace stress.
Maintaining good psychological and emotional health is essential for job performance and minimizing absenteeism.Studies reveal that PPD is associated with increased workplace absenteeism, reduced job performance, and higher disability costs for employers (11).Mothers who experience PPD often face heightened absenteeism, prolonged medical disability following childbirth, difficulties in re-adjusting to the work, and heightened relationship conflicts, including divorce (12).
Despite the importance of this issue, current research has insufficiently addressed the experiences of female workers, especially in China.While some studies have explored PPD among working mothers (13-15), they have not considered the specific characteristics of occupations and how these might impact PPD.Given the profound implications of PPD on maternal health, child development, and workplace dynamics, this study aims to analyze the prevalence of postpartum depression among women in different occupational categories in urban Beijing within 1 year of childbirth, and to explore the relationship between occupational factors and PPD.The research seeks to provide a comprehensive understanding of the factors influencing PPD in the context of working mothers, thereby guiding the development of targeted strategies to mitigate risks and support recovery.

Study setting and design
This research was conducted in six urban districts of Beijing, the capital city of China.Postpartum women are required to establish maternal and child health records within 1 week of childbirth at community health service centers.Over the following 3 years, these centers provide health checkups for infants in every 6 months, and vaccination services.Data were collected when a mother accompanied her one-year-old baby to the health center for a physical examination or vaccination.If the mother was not present, we contacted them by phone and sent the survey questionnaire via WeChat or SMS to complete the data collection.

Participants and recruitment
Cluster sampling was used to conduct a cross-sectional survey.Inclusion criteria of Postpartum women: (a) those who established maternal and child health records from November 2017 to June 2018 in 10 community health service centers across the six urban districts of Beijing; (b) women who were in the 1 year postpartum, with normal communication and understanding abilities; (c) those who voluntarily participated in the survey and signed an informed consent form.Exclusion criteria: Those previously or during pregnancy diagnosed with organic brain disease; those with a history of psychiatric disorders; and those who refused to participate after explanation.This study was approved by the Ethics Review Committee of the Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (067-2021).

Data collection
Data on these women for 1 year postpartum were collected from November 2018 to June 2019.After the respondents signed the informed consent form, they were enrolled in the study.Data collection was initiated with a digital questionnaire.A total of 589 cases met the inclusion criteria for the study, with 554 cases ultimately providing valid data, with an effective response rate of 94.06%.

Measurements
One-year postpartum data were collected using a two-part questionnaire.Part 1 focused on sociodemographic profile (age, education level, family and personal monthly income), employment factors (the women's occupational status and maternity leave), and postpartum factors (baby's health status, baby's feeding methods, and the women's caregiving status).Perinatal information such as mode of delivery, parity, and complications were recorded from the maternal and child health records in the community health center.
Part 2 was the Edinburgh Postnatal Depression Scale (EPDS) for mental health status measurement.The Chinese version of EPDS was used to determine the occurrence of PPD.The EPDS has a sensitivity of 85%, specificity of 77%, positive predictive value of 83%, split-half reliability of 85%, and a Cronbach's α coefficient of 0.87 (16).The subjects used a self-assessment method, selecting corresponding scores (0-never, 1-sometimes, 2-often, 3-always) on 10 items (mood, pleasure, self-blame, anxiety, fear, insomnia, coping ability, sadness, crying, and self-harm) (17).A total score of ≥13 points was diagnostic for PPD.

Classification of postpartum women's occupations
Referring to the occupational classification in socio-economic status studies (18-21), the occupational information collected from questionnaire was categorized into four groups: physical workers (PW, workers, agricultural/forestry/fishery/water conservancy production personnel, cleaning and sanitation workers, restaurant service personnel, retail salespersons, etc.), commercial enterprises (CE, stateowned enterprises, foreign-funded enterprises, and small and medium-sized enterprise workers, financial insurance and other commercial practitioners, etc.), professionals, government office & public institution employees (PGPE, medical staff, teachers, scientific and technical workers, cultural workers, professional and technical personnel, staff of state organs and institutions, etc.), and unemployed or self-employed (US).

Data analysis
All data were checked before entry and were double-entered, with statistical analysis performed using SPSS software version 27.0.Count data were described using frequency (percentage), analyzed using the χ 2 test, and post-hoc tests were conducted using the Bonferroni method for pairwise comparisons between groups; logistic regression analysis with forward stepwise was used to analyze factors related to PPD.The level of significance was α = 0.05, with p < 0.05 considered statistically significant.

General characteristics of postpartum women in four occupational categories
Among 554 postpartum women surveyed within 1 year after delivery, the majority were aged 30-34 years (35.56%).Among these, the unemployed or self-employment under the age of 25 were more prevalent (38.61%), while women working in commercial enterprises above the age of 35 were more common than in other groups (23.79%).The majority had received tertiary education, either at a college or undergraduate level (83.94%), with physical laborers and the unemployed or self-employed women more likely to have a high school education or less, compared to other occupations.The predominant range for family monthly income was between 10,000 and 30,000 RMB (54.69%), with women in commercial enterprises reporting higher family incomes than other categories (53.88%).Personal monthly income most commonly fell between 5,000 and 15,000 RMB (78.52%), with those in the commercial sector earning more than their counterparts in other categories.Additionally, women employed in commercial enterprises had a higher proportion of first childbirths, pregnancies that were well-prepared, mixed feeding practices, and hiring of nannies compared to other occupational categories.See Table 1 for details.

Prevalence of PPD among postpartum women of four occupational categories
Based on an Edinburgh Postnatal Depression Scale (EPDS) score of ≥13, the overall prevalence of PPD among the surveyed subjects was 29.42% (163/554 individuals).The prevalence of PPD in women employed in commercial enterprises was 39.81% (82/206 individuals), which was significantly higher than that of other occupational categories, with a statistically significant difference (χ 2 = 19.284,p < 0.01).See Table 2 for details.

Univariate analysis of PPD among postpartum women
Univariate analysis revealed that women over the age of 35 have a significantly higher proportion of postpartum depression (PPD) at 41.90% compared to other age groups (χ 2 = 11.860,p = 0.008).Families with an income between 10,000 to 30,000 RMB show a lower prevalence of PPD at 24.09% (χ 2 = 9.860, p = 0.007).Women with unintended pregnancies show the highest rate of PPD at 47.06%, which is statistically significant (χ 2 = 14.899, p = 0.001).Mothers of babies with health problems have a significantly higher rate of PPD compared to mothers of healthy babies (χ 2 = 20.567,p < 0.001).Women who choose formula or mixed feeding have a higher proportion of PPD at 35.67% (χ 2 = 13.632,p = 0.001).The prevalence of PPD among mothers who hire a nanny is significantly higher at 49.15%, compared to those who receive postpartum care solely from the couple themselves or with assistance from relatives (χ 2 = 25.873,p < 0.001).See Table 3 for details.

Logistic regression analysis of occupational-related influencing factors of PPD in postpartum women
In the regression analysis, occupation was initially incorporated as an independent variable to explore whether any specific occupational group was associated with an increased risk of PPD in the sample.After adjusting for age, education level, and monthly family income, and further adjusting for pregnancy preparation, baby's health condition, breastfeeding method, and postpartum care, it was found that employees in commercial enterprises (OR = 4.184, 95% CI: 1.036-5.247,p = 0.041) were positively associated with an increased risk of PPD compared to the US group (Table 4).
Using PPD as the dependent variable, further logistic regression analysis was conducted with family monthly income, personal monthly income, length of maternity leave, care condition, and feeding method as independent variables.The results, after adjusting for age, educational level, and further adjusting for perinatal factors such as parity, whether the pregnancy was well-prepared, and baby's health status, indicated that factors significantly associated with PPD are presented in Table 5.

High prevalence of PPD in urban Beijing
This study reveals that the prevalence of PPD in women within 1 year postpartum in the urban areas of Beijing is 29.42%.Compared to the global prevalence of PPD, which ranges from 2.1 to 31.6% (22,23), and recent surveys in China indicating a detection rate of PPD between 3.7 and 34.7%, this figure is notably high (6).The variance in reported PPD prevalence rates can be attributed to the use of different assessment tools and cut-off values (6,22,23), highlighting the need for standardized methods in future research.Meanwhile, this study included postpartum women living and working in the six urban districts of Beijing.The high incidence of PPD in urban Beijing may be attributed to the fast pace of life, intense competition, and significant work and economic pressures (24).

Occupational differences and PPD prevalence
In this study, the prevalence of PPD among women employed in commercial enterprises was found to be 39.81%, significantly higher than that of physical workers (18.92%), professionals, government office & public institution employees (21.97%), and the unemployed or self-employed (28.71%).This disparity underscores the substantial differences in the prevalence of PPD among postpartum women of various occupations, highlighting the necessity of focusing on PPD from an occupational perspective.Women working in commercial enterprises are often exposed to greater pressures of competition and unemployment, which might be associated with higher rates of PPD (25,26), and their psychological state, particularly postpartum mental health, requires special attention.In this study, women in commercial enterprises tended to be older compared to other groups, which may be associated with the higher incidence of PPD.Research has found that older postpartum women have a higher incidence of postpregnancy complications and poorer postpartum recovery; on the other hand, older mothers tend to have more concerns, which may lead to greater mental stress, resulting in anxiety, depression, and other adverse emotional states (27,28).Furthermore, the proportion of first-time mothers was higher among those in commercial enterprises.As novice mothers, the lack of experience in childbirth and postpartum baby care can also lead to postpartum depression (29, 30).

Multiple factors influencing PPD among working women
Further multivariate analysis revealed that women working in commercial enterprises are affected by a wider range of factors contributing to PPD.Among these, personal monthly income of 5,000-15,000 RMB was identified as risk factors.Multiple studies have found that PPD is related to the family's economic status (5,6,27,31,32).Both higher and lower family incomes may increase the incidence of PPD.This is consistent with the findings in this study regarding women in physical labor occupations, where family monthly income affects PPD.In this study, although the family monthly income of women in commercial enterprises was significantly higher than that of other occupational categories, no correlation was found with the occurrence of PPD.In contrast, the personal monthly income of the women was related to PPD.This suggests that women in commercial enterprises may focus more on their career development, which could lead to increased stress.
This study also found that maternity leave of less than 6 months significantly increases the risk of PPD for women in commercial enterprises.This aligns with the findings of other studies (9,10), which indicate that shorter maternity leave is associated with higher rates of postpartum depression.Adequate maternity leave is associated with improved recovery for the mother and potentially better care of the newborn.Therefore, ensuring sufficient maternity leave is an important way to protect the postpartum physical and mental health of working women (33).In China, maternity leave for mothers is divided into three parts: basic maternity leave, extended maternity leave, and local maternity leave.According to China's labor law regulations, female employees are entitled to 98 days of paid maternity leave.In special circumstances, such as in cases of dystocia, the leave can be extended by an additional 15 days.And in Beijing, female employees also enjoy an additional local 60 days of maternity leave.
However, in this study, maternity leaves shorter than 6 months were positively correlated with postpartum depression in women in commercial enterprises, indicating that current maternity leave policies require reasonable adjustments based on the specific characteristics of the occupation, and from the perspective of postpartum mothers' mental health.
There is an association between the method of infant feeding and the psychological state of the mother.In this study, compared to exclusive breastfeeding, mixed or formula feeding resulted in a higher prevalence of PPD among women in commercial enterprises and in professionals, government office & public institution employees.Conversely, for unemployed and self-employed women, mixed or formula feeding resulted in a lower prevalence of PPD.This may be because mixed or formula feeding, being more complex and troublesome, can increase anxiety more easily in those working women facing greater occupational stress (7).In Chinese culture, breastfeeding often extends up to 1 year or more.For working women, this practice poses significant challenges.Once maternity leave concludes, lactating women are required to frequently travel between home and workplace to breastfeed, a process that is both timeconsuming and physically draining, thereby exerting considerable  psychological pressure (34,35).Alternatively, many postpartum mothers returning to work opt to express breast milk using pumps and temporarily store it at the workplace for later use.However, societal stigmas surrounding breastfeeding, coupled with unfriendly and inadequate facilities at work, exacerbate the mental stress experienced by professional women (36).This situation underscores the need for more supportive breastfeeding environments tailored to the needs of working women (37,38).
The study also found that having relatives help with care is a protective factor against PPD.The presence of relatives to assist with care is associated with a lower prevalence of PPD among women in commercial enterprises and those in professionals, government office & public institution employees.The level of postpartum support is considered one of the most important influencing factors for PPD (39)(40)(41).This is particularly crucial for mothers returning to the workforce.Compared to hiring nannies, care and attention from family members provide the best psychological support for postpartum women.For Chinese parents, options for infant care are limited.Before the age of three, due to the lack of affordable public infant and toddler care facilities, caregiving predominantly takes place at home.Hiring a nanny entails additional financial burdens and concerns about the caregiver's qualifications.On the other hand, entrusting grandparents with childcare often leads to increased family conflicts.This scenario underscores the need for government bodies and workplaces to provide high-quality, trustworthy childcare services, which are particularly crucial for postpartum working women.The establishment of such services would alleviate the caregiving burden on families and support the mental and emotional well-being of working mothers.

Limitations
While this study provides valuable insights into the prevalence and factors associated with PPD in different occupational groups, it has its limitations.As a cross-sectional study, it cannot establish causality between identified risk factors and PPD.Future longitudinal studies are recommended to address this gap.Moreover, a more comprehensive analysis of occupational stress and its impact on PPD would enhance our understanding of the occupational-specific risks faced by these women.The reliance on self-reported data may introduce recall bias, suggesting the need for more objective measurement tools in future studies.

Conclusion
In conclusion, the higher prevalence of PPD in women employed in commercial enterprises, influenced by various occupational and personal factors, calls for further research and targeted intervention strategies.This study, with its focus on occupational factors, provides a novel perspective in analyzing the risk factors for PPD among working women in Beijing.The findings offer theoretical support for developing effective screening and intervention measures tailored to the needs of women in different occupations, aiming to promote their mental health and well-being postpartum.

TABLE 1
Characteristics and univariate analysis among four occupational categories of postpartum women.
PW, physical workers; CE, commercial enterprises; PGPE, professionals, government office & public institution employees; US, unemployed or self-employed.with the occurrence of PPD.For the unemployed and self-employed, mixed feeding (OR = 0.111-0.976,95%CI: 4.014, p = 0.045) was negatively correlated with the occurrence of PPD.

TABLE 2
The prevalence of PPD among four occupational categories of postpartum women.

TABLE 3
Univariate analysis of PPD among postpartum women.

TABLE 4
Logistic regression analysis of occupational groups affecting PPD among postpartum women.

TABLE 5
Logistic regression analysis of variables affecting PPD in four occupational groups of postpartum women.